how can i compare two images which are almost the same

hello!

I have a black and white binary image,i create a copy of this image and i compare these two images using histograms. The result is that these images are exactly the same.

I put a black dot(one pixel) somewhere in the first image an then i compare again the two images and of course the result is that they are not the same anymore.

the question is what can i do to compare two images who are generally the same,but they have very very small differences. Differences that you cant see with naked eyes.

Thank you very much

Answer 1

[tudor dima]

You could try

>> i3 = xor(i1, i2);

>> imagesc(i3):

% and for some relative measure

>> d = sum(i3(:)) / numel(i3);

Of course, this returns no spatial info, but I'm not sure what exactly are you looking for.

[alex]

you really helped me with your answer! actually in my case its more usefull the i3 = OR(i1, i2); thank you very much for the idea!